[PATCH v3 23/33] drm/vkms: Introduce configfs for connector type

Louis Chauvet
2025-12-22T10:12:26Z

Add a new attribute to connector to change its type. This is mostly
cosmetic and don't have direct effect in VKMS behavior.

Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
Documentation/ABI/testing/configfs-vkms | 7 ++++
Documentation/gpu/vkms.rst | 3 +-
drivers/gpu/drm/vkms/vkms_configfs.c | 65 +++++++++++++++++++++++++++++++++
3 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/configfs-vkms b/Documentation/ABI/testing/configfs-vkms
index 34cb6aeec411..5452140cc508 100644
--- a/Documentation/ABI/testing/configfs-vkms
+++ b/Documentation/ABI/testing/configfs-vkms
@@ -33,6 +33,13 @@ Description:
Connection status of the connector. Possible values:
1 - connected, 2 - disconnected, 3 - unknown.

+What: /sys/kernel/config/vkms/<device>/connectors/<connector>/type
+Date: Nov 2025
+Contact: dri-devel@lists.freedesktop.org
+Description:
+ Type of the connector. Possible values match those
+ exposed by the "type" field in drm_connector.
+
What: /sys/kernel/config/vkms/<device>/connectors/<connector>/possible_encoders
Date: Nov 2025
Contact: dri-devel@lists.freedesktop.org
diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
index 791c4f33a90a..41c6f4733663 100644
--- a/Documentation/gpu/vkms.rst
+++ b/Documentation/gpu/vkms.rst
@@ -138,10 +138,11 @@ Last but not least, create one or more connectors::

sudo mkdir /config/vkms/my-vkms/connectors/connector0

-Connectors have 1 configurable attribute:
+Connectors have 2 configurable attribute:

- status: Connection status: 1 connected, 2 disconnected, 3 unknown (same values
as those exposed by the "status" property of a connector)
+- type: Type of connector. Same values as exposed by the "type" field in drm_connector.

To finish the configuration, link the different pipeline items::

diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c
index e7f3ab54b5a1..d6a85d6c466f 100644
--- a/drivers/gpu/drm/vkms/vkms_configfs.c
+++ b/drivers/gpu/drm/vkms/vkms_configfs.c
@@ -1170,10 +1170,75 @@ static ssize_t connector_status_store(struct config_item *item,
return (ssize_t)count;
}

+static ssize_t connector_type_show(struct config_item *item, char *page)
+{
+ struct vkms_configfs_connector *connector;
+ int type;
+
+ connector = connector_item_to_vkms_configfs_connector(item);
+
+ scoped_guard(mutex, &connector->dev->lock) {
+ type = vkms_config_connector_get_type(connector->config);
+ }
+
+ return sprintf(page, "%u", type);
+}
+
+static ssize_t connector_type_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct vkms_configfs_connector *connector;
+ int val, ret;
+
+ connector = connector_item_to_vkms_configfs_connector(item);
+
+ ret = kstrtouint(page, 10, &val);
+
+ if (ret)
+ return ret;
+
+ switch (val) {
+ case DRM_MODE_CONNECTOR_Unknown:
+ case DRM_MODE_CONNECTOR_VGA:
+ case DRM_MODE_CONNECTOR_DVII:
+ case DRM_MODE_CONNECTOR_DVID:
+ case DRM_MODE_CONNECTOR_DVIA:
+ case DRM_MODE_CONNECTOR_Composite:
+ case DRM_MODE_CONNECTOR_SVIDEO:
+ case DRM_MODE_CONNECTOR_LVDS:
+ case DRM_MODE_CONNECTOR_Component:
+ case DRM_MODE_CONNECTOR_9PinDIN:
+ case DRM_MODE_CONNECTOR_DisplayPort:
+ case DRM_MODE_CONNECTOR_HDMIA:
+ case DRM_MODE_CONNECTOR_HDMIB:
+ case DRM_MODE_CONNECTOR_TV:
+ case DRM_MODE_CONNECTOR_eDP:
+ case DRM_MODE_CONNECTOR_VIRTUAL:
+ case DRM_MODE_CONNECTOR_DSI:
+ case DRM_MODE_CONNECTOR_DPI:
+ case DRM_MODE_CONNECTOR_SPI:
+ case DRM_MODE_CONNECTOR_USB:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ scoped_guard(mutex, &connector->dev->lock) {
+ if (connector->dev->enabled)
+ return -EBUSY;
+
+ vkms_config_connector_set_type(connector->config, val);
+ }
+
+ return count;
+}
+
CONFIGFS_ATTR(connector_, status);
+CONFIGFS_ATTR(connector_, type);

static struct configfs_attribute *connector_item_attrs[] = {
&connector_attr_status,
+ &connector_attr_type,
NULL,
};

--
2.51.2